blink: Cleanup core class forward declarations

third_party/WebKit/Source/core/animation/CSSLengthInterpolationType.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CSSLengthInterpolationType_h
 #define CSSLengthInterpolationType_h
 
 #include "core/animation/CSSInterpolationType.h"
 #include "core/animation/LengthPropertyFunctions.h"
 #include <memory>
 
 namespace blink {
 
 class ComputedStyle;
-class CSSToLengthConversionData;
 
 class CSSLengthInterpolationType : public CSSInterpolationType {
  public:
   CSSLengthInterpolationType(PropertyHandle);
 
   InterpolationValue maybeConvertUnderlyingValue(
       const InterpolationEnvironment&) const final;
   void composite(UnderlyingValueOwner&,
                  double underlyingFraction,
                  const InterpolationValue&,
@@ skipping 18 matching lines @@
   PairwiseInterpolationValue maybeMergeSingles(
       InterpolationValue&& start,
       InterpolationValue&& end) const final;
 
   const ValueRange m_valueRange;
 };
 
 }  // namespace blink
 
 #endif  // CSSLengthInterpolationType_h